CN111836606A

CN111836606A - Wound dressing

Info

Publication number: CN111836606A
Application number: CN201980018263.6A
Authority: CN
Inventors: 猪饲智范; 中野繁一
Original assignee: Nichiban Co Ltd
Current assignee: Nichiban Co Ltd
Priority date: 2018-03-16
Filing date: 2019-03-15
Publication date: 2020-10-27
Also published as: EP3766464A4; KR20200131828A; JP7295843B2; JPWO2019177156A1; TW201940142A; KR102635044B1; WO2019177156A1; TWI808139B; EP3766464A1

Abstract

The invention provides a wound dressing which can improve the visibility of a wound site and has the advantages of high absorption speed of exudate and appropriate retention amount of exudate. A wound dressing, characterized by: a super absorbent pad having a laminated structure of a polyester nonwoven fabric layer/a water absorbent layer, wherein the water absorbent layer is composed of super absorbent fibers, polypropylene fibers and a polyethylene binder, and the super absorbent pad has a through opening.

Description

Wound dressing

Technical Field

The present invention relates to a wound dressing for covering a wound site of the skin to create a good healing environment.

Background

Wound dressings are broadly classified into a repair material (modern wound dressings) and a medical material (conventional wound dressings) such as gauze, and the former is generally a medical material for covering and protecting a wound, a burn, a bedsore, or the like caused by trauma or surgery, and maintaining a moist environment of the wound to create an environment favorable for wound healing (hereinafter, the wound dressings in the present specification refer to such a medical material).

Generally, wound dressings are composed of an Absorbent pad such as a transparent film, an adhesive, and an opaque nonwoven fabric, and a polyurethane foam, and for example, patent document 1 discloses a wound bandage in which a nonwoven fabric layer composed of a moisture-permeable polyurethane layer, hydrophobic fibers, and Super Absorbent Fibers (SAF) are laminated.

Wound dressings have been proposed so far not only for protecting the wound site, but also mainly for absorbing and retaining exudate from the wound site to maintain the wound surface in a moist environment and create an environment favorable for wound healing, and from this viewpoint, materials and constitutions thereof may be variously selected. Further, it is necessary to select an appropriate type of wound dressing according to the healing process for replacement or the like, but in many of the wound dressings that have been proposed and put on the market so far, transparency is lacking, and therefore it is often difficult to observe (visually confirm) the healing process of the wound surface in a state where the wound dressing is stuck.

Patent document 2 discloses a wound dressing having a lattice structure provided with a material including at least one slit. The wound dressing of the same document aims to open the slit by applying a force perpendicular to the long axis of the slit and to visualize the wound through the resulting opening.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2000-175959

Patent document 2: japanese Kokai publication No. 2010-504835

Disclosure of Invention

Problems to be solved by the invention

In conventional wound dressings that have been proposed and put on the market so far, it is difficult for not only the dressings to observe and confirm (visually confirm) signs of healing condition of the wound surface and infection symptoms, and thus it is difficult to clarify the standard of dressing change. As disclosed in the cited document 2, in the system in which the slit is provided, it is necessary to stretch the wound dressing in order to open the slit as an opening, and the wound surface cannot be seen at a glance. Furthermore, given that the wound dressing is provided with holes that remain open at all times so that the wound site can be determined at all times, it is difficult to protect the wound in the portion of the holes and to retain exudate, it is difficult to maintain a moist environment that is favorable for wound healing, and it is possible that the strength and shape retention of the dressing itself may be affected.

Furthermore, even with conventional wound dressings, when exudate at the wound site increases due to the length of the wound site, the depth of the wound, and the manner of surgery, it may overflow from the wound dressing due to the inability to completely absorb the exudate.

As such, there is a need for a wound dressing that improves visibility of a wound site and has the advantages of a high absorption rate of exudate and a proper amount of exudate remaining.

Means for solving the problems

As a result of intensive studies to solve the above problems, the present inventors have found that a wound dressing having a super absorbent pad in which a water absorbent layer made of super absorbent fibers, polypropylene fibers and a polyethylene binder is laminated on a polyester nonwoven fabric as one of the configuration modes of the wound dressing and through-openings are formed in the super absorbent pad can achieve the advantages of good visibility of a wound site, a high absorption rate of exudate and an appropriate retention amount of exudate, and have completed the present invention.

That is, the present invention relates to a wound dressing,

1. the method is characterized in that: a super absorbent pad having a laminated structure comprising a polyester nonwoven fabric layer/a water absorbent layer, wherein the water absorbent layer is composed of super absorbent fibers, polypropylene fibers and a polyethylene binder, and the super absorbent pad has through openings.

Further, according to the present invention, the following embodiments are also provided.

2. The wound dressing comprises a water-absorbing layer and a wound dressing body, wherein the water-absorbing layer comprises, by mass, more than 30% by mass and less than 50% by mass of super-absorbent fibers, polypropylene fibers and a polyethylene binder, more than or equal to 40% by mass and less than 55% by mass, and more than 10% by mass and less than 30% by mass (wherein the total of the super-absorbent fibers, the polypropylene fibers and the polyethylene binder is 100% by mass).

3. The wound dressing is characterized in that the weight per unit area of the high-water-absorptivity absorption pad is 200-400 g/m²The thickness is 1.0-3.0 mm.

Furthermore, the invention relates to a wound dressing,

4. the method is characterized in that: a wound dressing having a super absorbent pad, wherein the super absorbent pad has a laminated structure of a nonwoven fabric layer/a water absorbent layer,

the super absorbent pad has a plurality of through openings over the entire surface of the pad.

Still further, according to the present invention, the following embodiments are further provided.

5. The wound dressing, wherein the size of each opening in the opening part is 10-500 mm²。

6. The wound dressing, wherein the opening has a triangular, quadrilateral, rectangular, parallelogram, rhomboid, circular, oval, crescent, horseshoe, donut or a combination thereof shape.

7. The wound dressing is characterized in that the total area of the upper surface of the super absorbent pad is 100%, and the total area of all the openings of the openings is 17% or more and 39% or less.

Effects of the invention

According to the present invention, it is possible to provide a wound dressing which can simultaneously achieve advantages such as good visibility of a wound site, a high absorption rate of exudate and an appropriate amount of exudate to be retained.

Drawings

Fig. 1 is a cross-sectional view of a super absorbent pad in a preferred embodiment of the present invention in a wound dressing.

Fig. 2 is a cross-sectional view of a wound dressing in a preferred embodiment provided by the present invention.

Fig. 3 is a schematic view (front view) showing an embodiment of the shape of the opening in the super absorbent pad used in the present invention.

Fig. 4 is a schematic view (front view) showing an embodiment of the shape of the opening in the super absorbent pad used in the present invention.

Fig. 5 is a schematic view (front view) showing an embodiment of a super absorbent pad used in the present invention.

Fig. 6 is a schematic view (front view) of a super absorbent pad used in example (test example 2).

Description of the reference numerals

1 high water absorption pad

2 Water-absorbing layer

3 polyester non-woven fabric

4 backing layer

5 surface layer

10 wound dressing

20 mucosa

21 adhesive layer

22 support layer

30(30A, 30B) Release Material

40 carrier film

50 adhesive plaster

Opening part A

B half cut

Detailed Description

The invention provides a wound dressing, which is characterized in that: a super absorbent pad having a laminated structure of a polyester nonwoven fabric layer/a water absorbent layer, wherein the water absorbent layer is composed of super absorbent fibers, polypropylene fibers and a polyethylene binder, and the super absorbent pad has through openings.

Further, the present invention provides a wound dressing characterized in that: a wound dressing comprising a super absorbent pad having a laminated structure of a nonwoven fabric layer/a water absorbent layer, wherein the super absorbent pad has a plurality of through openings formed over the entire surface of the pad.

Hereinafter, various constitutions of the wound dressing provided by the present invention will be described in detail.

(super absorbent pad)

< polyester nonwoven Fabric layer >

The polyester nonwoven fabric layer (hereinafter, also simply referred to as "nonwoven fabric layer") constituting the above-mentioned super absorbent pad plays a role in absorbing exudate at a wound site and allowing the exudate to permeate into a water-absorbent layer described later, and also plays a role in retaining exudate which is absorbed and gelled by the water-absorbent layer and preventing the exudate from returning to the wound site. Therefore, when the wound dressing provided by the invention is applied, the polyester non-woven fabric layer in the high-water-absorptivity absorption pad is closer to the wound surface side than the water-absorbing layer.

In addition, the polyester non-woven fabric layer also plays the following roles: when the openings described later are formed, the shape retention properties are imparted to the super absorbent pad without impairing the processability.

The polyester nonwoven fabric layer may be a nonwoven fabric produced by various processing methods such as a spunlace method, a spunbond method, a thermal bond method, a chemical bond method, an air-laid method, a melt-blown method, a needle-punching method, and a stitch-bonding method.

Further, as the polyester, polyethylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, polybutylene terephthalate, and the like can be cited.

Among them, a polyethylene terephthalate nonwoven fabric sheet produced by a spunbond method is preferably used as the nonwoven fabric layer from the viewpoints of liquid permeability, liquid absorbability, exudate gel product retention (prevention of back flow), shape retention and strength of a super absorbent pad when exudate is absorbed, workability in processing (opening, cutting, etc.) when manufacturing a wound dressing, and the like, in addition to cost and biocompatibility. Further, the use of the polyethylene terephthalate nonwoven fabric sheet produced by the spunbond method is also associated with an improvement in the lamination strength when a web composed of polyolefin is used in the surface layer described later.

The nonwoven fabric layer may have a suitable weight per unit area and thickness in consideration of liquid permeability, liquid absorbability, skin-attachment property, etc., for example, the weight per unit area is 10 to 30g/m²The thickness is 0.05 mm-0.3 mm.

< Water-absorbing layer >

The water absorbing layer is composed of high water absorbing fiber, polypropylene fiber and polyethylene adhesive.

The superabsorbent fibers gel by contact with exudate from the wound site and act to retain the exudate. Therefore, although the water absorption capacity can be increased by increasing the compounding ratio thereof, the gel strength is lowered, which may cause exudate (gel) to ooze out of the super absorbent pad. On the other hand, when the compounding ratio is reduced, although the shape retention property of the super absorbent pad is improved and the gel-like exudate can be prevented from overflowing, the water absorption amount is reduced, and the super absorbent pad may not completely absorb the exudate, which may cause the overflow.

The polypropylene fibers also contribute to shape retention of the water-absorbent layer, and the polyethylene binder improves adhesion between the super-absorbent fibers and the polypropylene fibers and contributes to shape retention of the water-absorbent layer. Therefore, by increasing their compounding ratio, the strength of the exudate gel formed by the super absorbent fibers can be increased, but this may also result in a decrease in the amount of water absorbed. On the other hand, when their compounding ratio is reduced, the water absorption capacity can be increased, but this may also result in lack of ability to retain exudates (gel), resulting in a decrease in shape retention of the super absorbent pad and spillage of exudates (gel).

As described above, the water absorption amount in the water-absorbing layer and the shape retention property evaluated as the gel strength of the exudate are contradictory properties, and therefore, in order to achieve both of these properties, it is necessary to select the compounding ratio of the super absorbent fiber, the polypropylene fiber, and the polyethylene binder (hereinafter, referred to as a hydrophobic material). From this viewpoint, it is preferable to set the compounding ratio (mass ratio) in the water-absorbent layer to, for example, the superabsorbent fiber to the hydrophobic material (polypropylene fiber and polyethylene binder) to be more than 30 mass% and less than 50 mass% and more than 50 mass% and less than 70 mass% (wherein the total of the superabsorbent fiber and the hydrophobic material is 100 mass%).

Among these, 31 to 49 mass%, 51 to 69 mass%, and particularly preferably 33 to 43 mass%, and 57 to 67 mass% of the hydrophobic material are used as the superabsorbent fibers (the total of the superabsorbent fibers and the hydrophobic material is 100 mass%), whereby a water-absorbent layer having an excellent balance between water absorption capacity and gel strength and a superabsorbent absorbent pad can be obtained.

In addition, from the viewpoint of the adhesiveness between fibers (shape retention property is provided) of the polyethylene binder, the mass ratio of the polypropylene fibers and the polyethylene binder constituting the hydrophobic material is set to, for example, 5:1 to 1:3, preferably 3:2 to 1:1, and more preferably 3:1 to 1:1, of the polypropylene fibers and the polyethylene binder.

From the above, for example, as an example of the compounding ratio (mass ratio) of the super absorbent fiber, the polypropylene fiber and the polyethylene binder, the super absorbent fiber, the polypropylene fiber and the polyethylene binder are preferably more than 30 mass% and less than 50 mass%, 40 mass% or more and less than 55 mass%, and more than 10 mass% and less than 30 mass% (wherein the total value of the super absorbent fiber, the polypropylene fiber and the polyethylene binder is 100 mass%).

More preferably, the high water absorption fiber is polypropylene fiber, polyethylene adhesive 31-49 wt%, 41-50 wt%, 11-19 wt%; more preferably 33 to 40% by mass, 45 to 50% by mass, and 15 to 17% by mass (the total of the super absorbent fibers, the polypropylene fibers, and the polyethylene binder is 100% by mass).

Super absorbent fiber

The super absorbent fibers used in the present invention include super absorbent polymer fibers shown below, and can also be used as composite fibers made of 2 or more of these super absorbent polymer fibers.

Examples of the super absorbent polymer include synthetic polymers such as polyacrylic acid (salt), polysulfonic acid (salt), maleic anhydride (salt), polyacrylamide, polyvinyl alcohol, and polyethylene oxide, polymers derived from natural products such as polyaspartic acid (salt), polyglutamic acid (salt), alginic acid (salt), starch, and cellulose, crosslinked products thereof, and composites (copolymers) thereof. Among them, sodium polyacrylate-based polymers are preferably used from the viewpoint of excellent liquid absorption performance.

Polypropylene fiber

The polypropylene fibers function to impart shape retention to the water-absorbent layer.

The polypropylene fiber may be used in the form of a core-sheath type composite fiber in which the core is made of polypropylene and the sheath is made of polyethylene, that is, a composite fiber coated with a polyethylene binder described later.

Polyethylene adhesive

The polyethylene binder plays a role in improving the adhesion between the super absorbent fibers and the polypropylene fibers and imparting shape retention to the water-absorbent layer.

Production of Water-absorbing layer

The method for producing the water-absorbent layer is not particularly limited, and for example, the super absorbent fibers, the polypropylene fibers, and the polyethylene binder may be mixed and processed into an appropriate mat shape.

In addition, by increasing the thickness of the water-absorbing layer or decreasing the density of the water-absorbing layer, the amount of water absorption increases, and the gel strength (shape retention) of exudate decreases. As described above, by adjusting the thickness and density of the water-absorbent layer, the water absorption capacity and shape retention property of the wound dressing can be changed depending on the type, thickness, basis weight and density of the polyester nonwoven fabric constituting the super absorbent pad and other layers (surface layer, backing layer, etc.) described later, although the water absorption capacity and shape retention property are changed. Further, the pressure bonding strength (thickness, weight per unit area, density) of each layer in the production of the super absorbent pad can be varied.

Therefore, for example, the water-absorbing layer is manufactured by setting the thickness of the water-absorbing layer to about 1.5 to 3.0mm and the unit area weight to 190 to 300g/m²On the left and right sides, the adjustment can also be carried out according to the thickness of the whole absorption pad and the unit area weight of the absorption pad in the subsequent process of manufacturing the high-water-absorptivity absorption pad.

The thickness of the super absorbent pad can be set to 1.0 to 3.0mm, and the unit area weight can be set to 200 to 400g/m²。

The thickness and the basis weight of the polyester nonwoven fabric layer/water-absorbent layer laminate structure may be set in the same manner, but considering the case where another layer described later is provided, for example, in the production of the laminate structure, the thickness may be set to about 1.5 to 3.0mm and the basis weight may be set to 200 to 350g/m²Left and right. When another layer (surface layer or back layer) described later is provided, the thickness and the weight per unit area of the entire super absorbent pad can be adjusted to fall within the above numerical range by adjusting the thickness and the weight per unit area of the other layer, the pressure-bonding force when the other layer is provided, or the like.

< other layer >

The super absorbent pad used in the wound dressing of the present invention may have a plurality of layers in addition to the polyester nonwoven fabric layer/the water absorbent layer laminate structure.

For example, as a layer closer to the wound surface than the polyester nonwoven fabric layer, a surface layer directly contacting the wound site or a backing layer on which the water-absorbent layer is mounted may be provided. At this time, a surface layer is laminated on the side opposite to the side on which the water-absorbing layer is provided on the polyester nonwoven fabric layer, and a backing layer is laminated on the side opposite to the side on which the polyester nonwoven fabric layer is provided on the water-absorbing layer.

Further, second and third water-absorbent layers and other layers (for example, second and third backing layers on which the second and third water-absorbent layers are laminated) may be provided between the surface layer and the polyester nonwoven fabric layer and between the water-absorbent layer and the backing layer.

As an example, fig. 1 shows a preferred embodiment of a super absorbent pad used in the wound dressing provided by the present invention.

As shown in fig. 1, the super absorbent pad 1 has the above-described laminate structure of the polyester nonwoven fabric layer 3/the water absorbent layer 2, the surface layer 5 is provided on the surface opposite to the surface provided with the water absorbent layer 2 of the polyester nonwoven fabric layer 3, and the backing layer 4 is provided on the surface opposite to the surface provided with the polyester nonwoven fabric layer 3 of the water absorbent layer 2. Here, the upper side (surface layer 5) in fig. 1 is a layer in direct contact with the wound site.

In addition, although not shown in fig. 1, between the surface layer 5 and the polyester nonwoven fabric layer 3, between the polyester nonwoven fabric layer 3 and the water-absorbent layer 2, and between the water-absorbent layer 2 and the backing layer 4, a hot-melt resin of polyethylene powder or the like may be provided to enhance adhesiveness (hot-melt property) between both layers according to the respective needs.

Although not shown in fig. 1, the super absorbent pad 1 is provided with openings (see fig. 2 described later) penetrating the absorbent pad 1.

Hereinafter, the super absorbent pad having a laminate structure of the surface layer 5/the polyester nonwoven fabric layer 3/the water absorbent layer 2/the backing layer 4 shown in fig. 1 in the preferred embodiment of the present invention will be referred to as "super absorbent pad a".

(in addition, "super absorbent pad" is an embodiment including "super absorbent pad A").

The material of the surface layer is not particularly limited as long as it does not inhibit the liquid absorbability of the polyester nonwoven fabric layer and the water-absorbent layer, and the surface layer may have a porous structure (for example, nonwoven fabric, mesh, punching process, etc.) in order to promote the penetration of liquid.

For example, a net made of polyolefin such as polyethylene or polypropylene may be used as the surface layer. In consideration of the liquid absorbing ability of the water-absorbent layer and the skin (wound site) conformability, it is preferable to use a weight per unit area of 10 to 30g/m²Left and right polyethylene mesh.

As used herein, "surface" refers to the side that is used as the side that exudate first permeates when using the wound dressing provided by the present invention.

Further, as the backing layer, while functioning to retain the exudate which is absorbed and gelled by the water-absorbent layer and to prevent the exudate from overflowing from the water-absorbent layer, it also functions in the following respects: when the openings described later are formed, the shape retention property is imparted to the super absorbent pad without impairing the processability.

Further, when a mucous membrane described later is used as a means for fixing the super absorbent pad to the wound site in the wound dressing by providing the backing layer, the anchorage property of the mucous membrane (adhesive layer described later) can be cited. Further, since the exudate gelled in the water-absorbent layer can be prevented from directly contacting the mucous membrane (adhesive layer), the detachment of the super absorbent pad from the mucous membrane due to the contact between the gelled exudate and the mucous membrane can be suppressed.

In addition, although the presence of the backing layer may deteriorate the moisture permeability of the super absorbent pad, in the present invention, the desired moisture permeability can be secured by forming the openings on the super absorbent pad.

The backing layer is not particularly limited as long as it has the above-described properties, and for example, a film or sheet made of polyolefin such as polyethylene or polypropylene can be used. In view of the liquid absorbability of the water-absorbent layer and the skin (wound site) conformability, for example, a weight per unit area of 10 to 50g/m is preferably used²The polyethylene film of (1).

< production of highly Water-absorbent pad >

The super absorbent pad (for example, super absorbent pad a) used in the wound dressing of the present invention is not particularly limited as long as it comprises the polyester nonwoven fabric layer/water absorbent layer laminate structure.

For example, after the water-absorbing layer is manufactured, the water-absorbing layer and a polyester nonwoven fabric layer may be laminated, and further, if necessary, other layers may be further laminated: surface layers such as polyolefin nets, and lining layers such as polyolefin films.

The water-absorbent layer and the polyester nonwoven fabric layer, the polyester nonwoven fabric layer and the surface layer, and the water-absorbent layer and the backing layer may be bonded (bonded) by thermal fusion bonding with a hot press roll. Further, when the hot-melt property in these layers is insufficient, a hot-melt resin may also be provided between the layers to enhance the adhesion (hot-melt property) between the two layers.

The area of the super absorbent pad can be appropriately determined, and in consideration of the area of the wound site, for example, it can be set to 10 to 300cm²Within the range.

The shape of the super absorbent pad itself is not particularly limited, and various shapes such as a square shape (square, rectangular, etc.), a quadrangle shape (trapezoid, rhombus, etc.), a polygon shape, a circle shape, an oval shape, a semicircle shape, a triangle shape, a crescent shape, and a combination thereof may be selected depending on the attachment site.

In addition, in the embodiment of the produced super absorbent pad, for example, the super absorbent pad A having the laminated structure of the surface layer 5/the polyester nonwoven fabric layer 3/the water absorbing layer 2/the backing layer 4, the weight per unit area is 200 to 400g/m²Preferably 290 to 360g/m²The thickness is 1.0 to 3.0mm, preferably 1.2 to 2.0 mm.

< openings of highly absorbent pad >

In the wound dressing provided by the invention, the following characteristics are provided: the high water absorption pad is provided with a through opening.

In the present invention, the opening portion is formed in a penetrating state (a state of always being opened), for example, in a slit shape, that is, the opening portion can be expanded (opened) only by stretching the wound dressing, but a slit-shaped object in a closed state as it is (unstretched) is not included.

In this way, by forming the through opening on the super absorbent pad, the wound part can be visually confirmed from the opening without peeling off the wound dressing, and the healing state of the wound surface and the sign of infection can be observed, and the timing of changing the wound dressing and the execution or revision of the wound treatment plan can be determined.

Further, by processing the openings, the flexibility of the super absorbent pad can be improved, and the surface area around the openings can be increased, thereby increasing the water absorption rate.

The opening section enables sufficient confirmation of the wound section, and the deformation amount of the opening section is small at the time of manufacturing the wound dressing, and the super absorbent pad as the wound dressing can maintain appropriate mechanical strength, and can ensure sufficient water absorption as the wound dressing, and at the same time, the size and shape thereof are appropriately selected for ensuring strength and shape retention for maintaining the shape thereof at the time of absorbing exudate.

For example, each of the openings has a size of 10 to 500mm²Preferably 50 to 400mm². The total area of all the openings is set to 17% or more and 39% or less, preferably 20% to 33% (also referred to as an open area ratio or an open area) with respect to the total area (100%) of the upper surface of the super absorbent pad. A plurality of the opening portions may be formed in one super absorbent pad provided on one wound dressing, and in this case, it is sufficient if the total area of the plurality of opening portions is within the above numerical range.

The shape of the opening is not particularly limited, and may be a polygonal shape such as a triangle, a quadrangle, a rectangle, a parallelogram, or a rhombus, or may be a shape including an arc such as a circle, an ellipse, a semicircle, a crescent, a horseshoe, or a circular ring, or a combination thereof. For example, from the viewpoint of ensuring the visibility of the opening, reducing the deformation amount of the opening, and maintaining the strength of the super absorbent pad, the shape may be such that the long sides of the opening are inclined with respect to the long sides of the super absorbent pad.

The opening may be formed by cutting the super absorbent pad to a predetermined size in one wound dressing and then processing the super absorbent pad to form a through opening in the super absorbent pad, or may be formed by cutting the super absorbent pad to a predetermined size in one wound dressing after processing the super absorbent pad to form a through opening in the super absorbent pad.

As an example, fig. 3 and 4 show various embodiments of the opening shape. Fig. 3 (I) to (IX) and fig. 4 (X) to (XVIII) show schematic views (front views) of the super absorbent pad for forming the through openings, respectively, and in each figure, the openings are indicated by oblique lines. The number and arrangement (vertical and horizontal directions) of the openings shown in the drawings are not limited to these.

For example, as shown in fig. 3, (I) a triangle, (II) a quadrangle (diamond), (III) a hexagon, (IV) a rectangle, (X) a rectangle (oblique), (XI) a parallelogram, (XII) a circle, (XIII) an ellipse, and (IX) an ellipse (oblique); as shown in fig. 4, the opening portions may be formed in a vertically and horizontally aligned manner as shown in (XIII) and (XVI) to (XVIII) of fig. 4, and examples thereof include (X) an oblong shape, (XI) an oblong shape (inclined shape), (XII) a semicircular shape, (XIII) a quarter circular shape, (XIV) a horseshoe shape, and (XV) an L shape.

Among them, a preferred embodiment of the opening is shown in fig. 5. Fig. 5 is a schematic view (front view) of a super absorbent pad, and in a rectangular super absorbent pad 1, a plurality of openings a are formed in a shape (parallelogram) inclined at an angle θ with respect to a longitudinal width 1a of the pad 1.

In this way, for example, when the opening portion is formed in a shape in which the axial direction of the opening portion is inclined with respect to one axial direction of the super absorbent absorption pad, in the case where the super absorbent absorption pad is cut into a predetermined size after the processing is performed so that the opening portion is formed in the super absorbent absorption pad, there is an advantage in that the strength of the absorption pad is easily maintained in the series of processing operations. Further, since the shape of the inclined opening improves the rigidity and flexibility of the absorbent pad, the absorbent pad is less likely to be deformed when the absorbent pad is cut and processed for manufacturing a wound dressing. Further, there is an advantage that chipping (powder) is not easily generated when the absorbent pad is cut after the opening portion is formed. Further, the super absorbent pad can be made to contact the wound site uniformly, that is, the wound surface can be made to contact the exudate absorbing surface (in other words, the portion of the super absorbent pad not opened) uniformly.

Further, for example, as shown in fig. 5, when it is a rectangular super absorbent pad, by making the width direction edge (a1) of the opening parallel to the long side width (1a) of the super absorbent pad, in short, by providing the opening edge so as to be parallel to the edge of the super absorbent pad, when the wound dressing is applied to a wound site, it is easy to grasp the position of the opening with respect to the wound site and to facilitate its application to an appropriate site.

(wound dressing)

The wound dressing provided by the present invention is not particularly limited in its structure as long as it has a super absorbent pad for forming the through opening.

For example, a fixing means (for example, an adhesive film including a support layer and an adhesive layer) for fixing the super absorbent pad to a wound portion, a release material (a release sheet or release paper) for protecting (preventing adhesion of dust or the like) an application surface (the above surface layer or the like) of the super absorbent pad immediately before application and releasing the super absorbent pad at the time of application, a carrier film (also referred to as a backing film) for improving handling of the wound dressing, and an adhesive tape for assisting in releasing the carrier film may be provided.

In addition, although only the super absorbent pad is finally applied (stuck) to the wound site and the peripheral skin of the wound site, and in a preferred embodiment, the super absorbent pad is used as a fixing device for the super absorbent pad, the super absorbent pad is referred to as a "wound dressing" in this specification including the release material, the carrier film, the adhesive tape, and the like that are released at the time of application.

Hereinafter, as an example of one preferred embodiment of the wound dressing provided by the present invention, fig. 2 shows a sectional view thereof.

As shown in fig. 2, as an example of a preferred embodiment, the wound dressing 10 is provided with a mucous membrane 20 as a fixing means for fixing the super absorbent pad 1 to the skin around the wound portion in addition to the super absorbent pad 1 (see fig. 1) (the super absorbent pad 1 and the mucous membrane 20 become wound dressings in a narrow sense after application). The super absorbent pad 1 is formed with openings a so as to penetrate through the pad in the stacking direction. The adhesive film 20 is composed of at least an adhesive layer 21 and a support layer 22. In the super absorbent pad 1, the backing layer 4 (not shown) of the absorbent pad 1 is adhered to the adhesive layer 21 of the mucous membrane 20. Further, a carrier film 40 is provided on the surface of the super absorbent pad 1 to which the super absorbent pad is applied (surface layer 5, not shown in the drawings), and the surface of the adhesive film 20 opposite to the side of the super absorbent pad 1, on which the release material 30(30A, 30B) for protecting the adhesive layer 21 in the adhesive film 20 is provided immediately before application, and a tape 50 is provided on the carrier film 40. In the present embodiment, the release member 30 is made of 2 sheets of material 30A having a large area and 30B having a small area. Preferably, a half-cut B is provided on the carrier film 40 and the adhesive plaster 50, and by cutting the carrier film 40 and the adhesive plaster 50 with this half-cut B, the carrier film 40 (and the adhesive plaster 50) in the vicinity of the half-cut B is easily brought into a prestretched state, and the carrier film 40 (and the adhesive plaster 50) can be easily peeled off from the adhesive film 20.

< mucous membranes >

The adhesive film has a laminated structure of at least two layers, which has a support layer and an adhesive layer provided on the surface thereof.

The mucosa functions in securing the superabsorbent absorbent pad to the wound site, and in a preferred embodiment it is adhered to the backing layer of the superabsorbent absorbent pad, and prior to application it may also be adhered to a release material as described below.

Therefore, the adhesive film preferably has an area slightly larger than that of the super absorbent pad by one turn, and preferably has a size to adhere to a release material described later. For example, the area of the super absorbent pad may be set to 25% or more and 50% or less with respect to the area of the adhesive film. When the area of the super absorbent pad is too small (e.g., less than 20%) relative to the area of the mucous membrane, there is a possibility that the obtained water absorption is insufficient, and the skin may be irritated due to the large area of the adhesive layer that the mucous membrane adheres to the skin around the wound site. Further, when the area of the super absorbent pad is too large (for example, more than 50%) relative to the area of the mucous membrane, since the area of the adhesive layer that the mucous membrane adheres to the skin around the wound site is small, the adhesive force obtained for fixing on the wound site is insufficient, and there is a possibility of causing peeling.

The position of the adhesive film to the super absorbent pad is not particularly limited, and for example, the adhesive film may be adhered to the super absorbent pad at the center of the adhesive film, or may be adhered to the super absorbent pad at a portion outside the center of the adhesive film.

The support layer is not particularly limited as long as it has appropriate stretchability, flexibility, and strength and ensures transparency so that the wound area can be seen from the openings of the super absorbent pad, and a support layer having appropriate moisture permeability and antibacterial activity is particularly preferable. For example, films and foams of polyolefin, polyurethane, polyester, polyacrylic, and the like can be cited. Among them, from the above viewpoint, a polyurethane film is preferable.

When the support layer is a polyurethane film, it is preferable to use polyester or polyether-based polyurethane, and it is also preferable to use a film which does not easily swell when it comes into contact with water, a therapeutic liquid, or other liquid. From such a viewpoint, a polyether polyurethane film is preferably used.

The thickness of the polyurethane film is usually 1 to 100. mu.m, preferably 8 to 50 μm, and more preferably 10 to 40 μm.

When the thickness of the polyurethane film is less than 1 μm, the strength as the support layer is insufficient in addition to difficulty in film formation, and when the wound dressing is adhered to or peeled from an adherend (wound portion), the support layer may be damaged (broken). Further, when the thickness of the polyurethane film is too large, even if the thickness of the entire wound dressing is reduced, it is difficult to adhere closely along the skin surface having a fine uneven texture such as a furrows, the adherence with the adherend is deteriorated, and a lift-off corner is easily formed at the peripheral portion of the wound dressing, so that there is a possibility that a feeling of discomfort at the time of peeling off from the adherend and adhering is increased, and further, a liquid may be caused to overflow from the super absorbent pad.

The moisture permeability of the support layer of the adhesive film is, for example, 1,000g/m or more²Hr, preferably 2,000g/m or more²24 hr. Further, the upper limit of the moisture permeability of the support layer is not particularly limited, but is usually 10,000g/m or less²24hr or so, preferably not more than 8,000g/m²About 24 hr. Such a polyurethane film support having moisture permeability is used as a repair material, is known per se (e.g., Japanese patent laid-open publication No. 7-231910), and is commercially available.

The pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive containing a synthetic resin, and the synthetic resin contained in the pressure-sensitive adhesive is not particularly limited as long as it has low irritation to the skin, and pressure-sensitive adhesives containing acrylic, urethane, silicone, rubber, polyvinyl alcohol, polyamide, polyvinyl acetate, and other synthetic resins can be used. Among these binders, acrylic binders composed of acrylic resins; polyurethane adhesives such as polyether polyurethane and polyester polyurethane; silicone adhesives such as organopolysiloxanes and alkylaryl polysiloxanes; and rubber-based adhesives such as polyisobutylene, butyl rubber, styrene-butadiene copolymer (SBR), styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), and hydrogenated products of SBR. Among them, polyurethane-based adhesives are particularly preferable from the viewpoint of adhesiveness and skin irritation.

The thickness of the adhesive layer is suitably selected usually within the range of 5 to 180 μm, preferably within the range of 10 to 150 μm.

For example, in the adhesive film using a polyurethane film as a support layer and having a polyurethane adhesive layer provided thereon, the moisture permeability thereof is, for example, 2,000 to 5,000g/m²24hr, preferably 3,000 to 4,000g/m²24hr, etc.

< Release Material >

The wound dressing provided by the present invention may further comprise a release material. The release material is generally laminated on a layer (for example, a surface layer) in direct contact with a wound site in the super absorbent pad and on an adhesive layer of the mucous membrane present around the super absorbent pad, and serves to protect these layers and prevent adhesion of dust and the like immediately before application.

As the above-mentioned release material, those conventionally used in the technical field of wound dressings and adhesive materials can be used. For example, the following colorless or colored sheets can be listed: plastic films such as polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polypropylene (unstretched, stretched, etc.), polyethylene, polyurethane, polyvinyl chloride, polystyrene, etc.; high-grade paper, glassine paper, parchment paper, kraft paper and other paper and synthetic paper; release-processed paper obtained by coating the plastic film, paper, synthetic fiber, or the like with a release agent having a release property such as a silicone resin or a fluororesin; aluminum foil; laminated paper obtained by laminating these films and sheets in various ways, and laminated release paper obtained by coating a release agent on the laminated paper. In addition, the release material may be provided with irregularities to facilitate its removal from the wrapper.

The thickness of these release materials is not particularly limited, but is usually 10 μm to 1mm, for example, 20 μm to 500 μm, and preferably 40 μm to 200 μm.

The shape of the peeling material may be square, rectangular, circular, etc., and may be a shape with rounded corners as necessary. This size may be the same size as or slightly larger than the size of the mucosa in the wound dressing. The release material may be formed by one or more pieces of division, and the cut thereof may be formed by a straight line, a wavy line, a sewing machine line, and the release materials may be partially overlapped with each other.

< Carrier film >

In the adhesive film, when the thickness of the support layer is as thin as about 1 to 30 μm, it is preferable that a releasable carrier film is provided on the surface opposite to the adhesive layer formed on the support layer, because the handling as a wound dressing is improved.

As the carrier film, various films made of various thermoplastic resins such as polyester, polyurethane, polyethylene, polypropylene, ionomer, polyamide, polyvinyl chloride, polyvinylidene chloride, ethylene-vinyl acetate copolymer, thermoplastic polyester, and polytetrafluoroethylene are preferably used. The carrier film may be used in a state in which the various films described above are laminated on a paper layer. Among them, a polypropylene film is preferably used from the viewpoint of obtaining excellent handling of the wound dressing.

For the purpose of improving the handling properties of the wound dressing, a thin film having a large thickness is preferably used for the carrier film, or the carrier film may be made of a material having high elasticity. The thickness of the carrier film is usually from 10 μm to 500. mu.m, preferably from 20 μm to 250. mu.m. When the thickness of the carrier film is less than 10 μm, the support of the mucous membrane and the carrier film do not adhere sufficiently, and when the thickness of the carrier film exceeds 500 μm, the handling property is improved despite the sufficient adhesion to the support of the mucous membrane, however, the rigidity of the carrier film is too high, and for example, when the release material is peeled off at the time of use, and the super absorbent pad is stuck to the wound site, and the adhesive layer of the mucous membrane is stuck to the skin around the wound site, the adhesion to the wound site and the peripheral skin is poor, and the adhesion is insufficient.

On the carrier film, a half-slit process may be performed in the longitudinal direction, the transverse direction, or the oblique direction of the film. Rather than cutting the entire carrier film, half cuts may be made to leave small connections. By applying a half-cut process to the carrier film, the half-cut is cut when applying the wound dressing, so that the carrier film can be peeled off from the mucosa more easily.

< adhesive tape >

In the wound dressing provided by the present invention, an adhesive tape may be attached to the carrier film, that is, to the surface opposite to the side on which the adhesive film in the carrier film is provided. The tape is preferably adhered to a portion of the planar surface of the carrier film, and more preferably, the above-described half-slit process is preferably performed together with the carrier film.

By pasting the adhesive tape on the carrier film, the thickness (elasticity) of the pasted portion is increased, and therefore, by performing the half-cut processing to penetrate the adhesive tape and the carrier film, this half-cut is cut at the time of applying the wound dressing, so that the carrier film (and the adhesive tape) at the periphery of the half-cut can be peeled off more easily. Further, symbols or letters serving as peel marks may also be printed on the blanket.

The adhesive has a laminated structure of at least two layers, wherein the laminated structure includes an adhesive support and an adhesive layer provided on the surface thereof, and the various films listed in the above-mentioned < adhesive film > support layer and < carrier film > can be suitably used for the adhesive support, and the various adhesives listed in the above-mentioned adhesive layer of < adhesive film > can be used for the adhesive layer.

As an example of the method of applying the wound dressing provided by the present invention, an application example of the wound dressing 10 shown in fig. 2 is shown below. First, in the release agent 30, the release agent 30A having a large release area exposes the super absorbent pad 1 and a part of the adhesive layer 21 of the adhesive film 20. Then, the super absorbent pad 1 is applied to the wound site (wound surface), the excess release member 30B is peeled off, and the adhesive layer 21 of the mucous membrane 20 is stuck to the skin around the wound site, thereby fixing the super absorbent pad 1 to the wound site. Thereafter, a half cut B for providing the carrier film 40 and the adhesive plaster 50 was cut, and from this cut portion, the carrier film 40 and the adhesive plaster 50 were peeled off from the mucous membrane 20, so that the super absorbent pad 1 and the mucous membrane 20 were closely adhered to the wound portion and the peripheral portion thereof.

The wound dressing thus applied can absorb exudate and the like at the wound site on the super absorbent pad, and can retain (retain water) by gelling the exudate. Further, by forming the through openings in the super absorbent pad, the state of the wound site can be confirmed, and moisture permeability can be ensured.

In this way, the wound dressing provided by the present invention is provided with visibility and high moisture permeability through the openings of the super absorbent pad, and can maintain the moist environment of the wound by absorbing and retaining exudate outside the openings, and can be expected to realize moist therapy (moist healing).

Examples

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(examples 1 to 7 and comparative examples 1 to 7)

[ method for producing highly Water-absorbent pad ]

In order to improve the thermal fusion property, polyethylene powder was attached to a polyester nonwoven fabric layer by a spunbond method, and fibers in which highly water-absorbent fibers (SAF), polypropylene fibers (PP), and polyethylene binder (PE) constituting a water-absorbent layer were mixed at a ratio shown in table 1 were gathered, and the fibers were bonded to each other by thermal fusion in an oven, thereby forming a water-absorbent layer and a laminate structure of the water-absorbent layer/the polyester nonwoven fabric layer.

Next, a polyolefin film (backing layer) coated with a hot melt adhesive was attached to the surface of the water-absorbent layer opposite to the side provided with the polyester nonwoven fabric layer.

Then, after the polyethylene net (surface layer) was heat-fused on the polyester nonwoven fabric layer, it was press-processed into a predetermined size (2 kinds, see below) so as to have an opening portion of a parallelogram, and a super absorbent pad (super absorbent pad a) was produced. In the evaluation of the performance of the super absorbent pad described later, an absorbent pad having no openings was used for the evaluation of the water absorption capacity and the gel strength.

As shown in table 1, the structures of the water-absorbent layer and the nonwoven fabric layer were changed, and the super absorbent pads in examples 1 to 7 and comparative examples 1 to 7 were manufactured according to the structures of the respective layers. Table 1 also shows the weight per unit area and the total thickness of the absorbent pad of the laminated structure (i.e., super absorbent pad a: polyolefin film (backing layer)/water absorbent layer/nonwoven fabric layer/polyethylene web (surface layer)) after the backing layer and the surface layer were provided, and the laminated structure (water absorbent layer/nonwoven fabric layer) before the backing layer and the surface layer were provided.

[ method for producing wound dressing ]

100 parts of a polyurethane adhesive and 2 parts of a crosslinking agent (Coronate L, Tosoh, Inc.) (formerly: manufactured by Nippon polyurethane industries, Ltd.) were uniformly mixed, then defoamed, coated on a polyester film (release body, thickness 50 μm) subjected to a release treatment using a blade coater to have a dry film thickness of 25 μm, and then cured and dried at 120 ℃ for 3 minutes to form an adhesive layer.

On the obtained adhesive layer, an ether-based urethane resin film substrate (moisture permeability of 3,300 g/m) having a thickness of 20 μm and serving as a support layer was allowed to stand²Day) was bonded to a surface of a laminate of a polypropylene film having a thickness of 40 μm and serving as a support film, the surface facing the support layer. Then, it was stored in a hot air drier at 50 ℃ for 5 days to complete the crosslinking reaction of the adhesive, thereby preparing an adhesive film having a carrier film for sticking to a peeling body.

The wound dressing having the release material was prepared by removing the release body of the mucous membrane, sticking the polyolefin film surface as the backing layer of the super absorbent pad cut to a predetermined size (the super absorbent pads in examples 1 to 7 and comparative examples 1 to 7, respectively, according to the respective layer structures) to the adhesive layer of the mucous membrane, sticking the release material (silicone-treated high-grade polyamide paper, having a thickness of 110 μm) so as to cover the adhesive layer of the mucous membrane and the super absorbent pad stuck thereon, and punching the same to a predetermined size.

< highly absorbent pad: production examples 1 and 2 having different shapes (sizes) >

For each of examples 1 to 7 and comparative examples 1 to 7, 2 kinds of super absorbent pads (1) and (2) having the following dimensions and opening portions were manufactured.

Production example 1: high water absorption pad (1)

Absorbent pad size: short side width (FIG. 5: 1b)30mm

The width of the long side (FIG. 5: 1a) is 65mm

Absorbent pad structure: examples 1 to 7 and comparative examples 1 to 7 (see Table 1)

Shape of opening: 5mm long (FIG. 5: A1) by 12mm high (FIG. 5: A2)

Opening inclination angle (FIG. 5: θ): 40 degree

Opening interval (FIG. 5: A3): 6mm

Area ratio of opening portion in super absorbent pad: 20 percent of

Production example 2: high water absorption pad (2)

Absorbent pad size: short side width (FIG. 5: 1b)50mm

The width of the long side (FIG. 5: 1a) is 100mm

Shape of opening: 10mm long (FIG. 5: A1) by 30mm high (FIG. 5: A2)

Opening inclination angle (FIG. 5: θ): 40 degree

Opening interval (FIG. 5: A3): 12mm

Area ratio of opening portion in super absorbent pad: 27 percent of

< wound dressing: production examples 3 and 4 having different shapes (sizes) >

Wound dressings (1) and (2) having the following dimensions were produced using the super absorbent pads (1) obtained in production example 1 described above [ 14 types in total in examples 1 to 7 and comparative examples 1 to 7, and 14 types in total in terms of the respective layer structures) and the super absorbent pads (2) obtained in production example 2 [ 14 types in the same manner ]. In addition, in any wound dressing, the absorbent pad is disposed near the center of the mucosa when disposed.

Production example 3: wound dressing (1)

The absorbent pad used: high water absorption pad (1)

Wound dressing (mucosal) size: short side width of 60mm

The width of the long side is 100mm

Production example 4: wound dressing (2)

The absorbent pad used: high water absorption pad (2)

Wound dressing (mucosal) size: short side width 90mm

The width of the long side is 150mm

[ evaluation of Properties of super absorbent pad ]

The water absorption capacity of the super absorbent pads in examples 1 to 7 and comparative examples 1 to 7, the gel strength when the absorbent pads absorb water, whether or not paper dust is generated during processing of the absorbent pads, and the suitability for cutting in the hole forming process were evaluated according to the following procedures.

In the examples, the evaluation was carried out using a super absorbent pad obtained by laminating a polyethylene net as a surface layer and a polyolefin film as a back layer, and it was confirmed that the surface layer and the back layer did not affect various properties such as water absorption amount.

[1] Evaluation of Water absorption

< evaluation step >

Each of the produced super absorbent pads A (having no opening part, including the surface layer and the back layer) was cut into 50mm X50 mm, and then 0.9 mass% of a saline solution was absorbed and prepared, and the pad was allowed to stand for 2 hours. The mass of the super absorbent pad was measured after standing for 2 hours before and after water absorption, and the calculated value was obtained by converting the amount of saline absorbed by the super absorbent pad per unit area.

Further, with respect to a commercially available product (wound dressing having an opening portion), the release material portion was peeled off, the absorbent pad was allowed to absorb the saline solution after the absorbent pad portion was placed upward, excess water which was not absorbed was wiped off after standing for 2 hours, and the water absorption amount per unit area (0.16 g/cm) was calculated in accordance with the same procedure²) Considering that the area of the openings of the commercially available product was about 30% of the entire area, the water absorption capacity of the commercially available product without openings was estimated to be 0.23g/cm²And sets the value as a target value. Then, whether or not the water absorption capacity per unit area of the super absorbent pad (without openings) provided by the present invention satisfiesThe target value is used as a judgment standard.

The number of tests n was set to 3, and the evaluation was performed by the average value (table 1 shows the range of the difference between the maximum value and the minimum value).

< evaluation criteria >

O: greater than or equal to 0.23g/cm²

X: less than 0.23g/cm²

[2] Evaluation of gel Strength

< evaluation step >

Each of the produced super absorbent pads (not having an opening portion, including a polyethylene net as a surface layer) was cut into 50mm X50 mm, and then 0.9 mass% saline was absorbed and prepared, and left to stand for 2 hours. After standing, a1,000 g/50mm phi weight was placed on a super absorbent pad to evaluate the exuded area of the gel.

< evaluation criteria >

Good: the exudation area of the gel is less than 5% of the area of the absorbent pad

X: the exudation area of the gel is 5-10% of the absorbent pad

X: the exudation area of the gel is 10% or more of the absorbent pad area

[3] Evaluation on paper dust production

< evaluation step >

With respect to the super absorbent pads (1) manufactured in the above-described manufacturing example 1 of different sizes (according to the structures of the respective layers, examples 1 to 7 and comparative examples 1 to 7), whether paper dust is generated at the time of punching the opening portion and at the time of implanting the absorbent pad into the mucous membrane was evaluated.

< evaluation criteria >

O: no paper dust is generated during punching of the opening and implantation of the absorbent pad

X: paper dust is generated during punching of the opening and during implantation of the absorbent pad

[4] Suitability for cutting in hole-opening processing

< evaluation step >

With respect to the super absorbent pads (1) manufactured in the above-described manufacturing example 1 of different sizes (according to the structure of each layer, examples 1 to 7 and comparative examples 1 to 7), whether the hole (opening) processing and the cutting processing can be performed or not was evaluated by the dimensional stability.

For suitability in drilling, the offset length of the opening interval (pitch) was measured.

Further, regarding the suitability in the cutting process, when the material is cut to a predetermined size, the offset length of the size is measured.

< evaluation criteria >

X: the offset length of the pitch is 1.0mm or more,

and the offset length of the cutting size is more than or equal to 1.5mm

And (delta): the offset length of the pitch is 0.5mm or more and less than 1.0mm,

and the offset length of the cutting size is more than or equal to 1.1mm and less than 1.5mm

O: the offset length of the pitch is less than 0.5mm,

and the offset length of the cutting size is less than 1.1mm

The results obtained above are shown in table 1.

[ Table 1]

< test example 2: evaluation of Water absorption and visibility by the Change in open area ratio (open area) >

In order to evaluate the relationship between the open area ratio (open area), the water absorption capacity, and the visibility, in a super absorbent pad having a plurality of openings of the same shape formed therein, the open area ratio (open area) was changed by changing the interval (pitch) of each opening, and the water absorption capacity, the visibility, and the suitability in cutting the opening were evaluated.

As described below, the super absorbent pads in the wound dressings used for evaluation had a certain size (absorbent pad size), absorbent pad structure and opening shape (size), and the opening ratio and the opening area of one absorbent pad were changed only by changing the intervals (pitches) of the respective openings shown in table 2 (a 3 in fig. 6 (fig. 5)). Fig. 6 is a schematic view (front view) showing the hole patterns of the super absorbent pads used in example a (fig. 6(a)), example E (fig. 6(b)), and example J (fig. 6(c)) shown in table 2.

Absorbent pad size: short side width (FIG. 5: 1b)50mm

The width of the long side (FIG. 5: 1a) is 100mm

Absorbent pad structure: example 1 (super absorbent pad A: comprising a surface layer and a backing layer)

Shape of opening: 10mm long (FIG. 5: A1) by 30mm high (FIG. 5: A2)

Opening inclination angle (FIG. 5: θ): 40 degree

Wound dressing size (mucosal size): short side width 90mm

The width of the long side is 150mm

Mucosal composition: polyurethane film (thickness) 0.018mm

Polyurethane adhesive (thickness) 0.025mm

Further, the water absorption capacity, visibility and suitability in open hole cutting were evaluated in the following manner.

Water absorption

< evaluation step >

The wound dressing was peeled off at the release material portion, and after placing the super absorbent pad facing upward, the super absorbent pad was allowed to absorb (having an opening portion, from the polyethylene mesh side as the surface layer) the saline solution prepared at 0.9 mass%, and left to stand for 2 hours. Excess water not absorbed was wiped off after 2 hours, and the mass of the wound dressing was measured after standing for 2 hours before and after water absorption, and the amount of saline absorbed by the super absorbent pad in the wound dressing was converted into the amount per unit area and calculated.

The water absorption capacity per unit area (0.16 g/cm) of a commercially available product (having openings) was calculated in accordance with the same procedure²) And set it as the target value.

< evaluation criteria >

X: less than 0.16g/cm²

O: greater than or equal to 0.16g/cm²

Visibility

< evaluation step >

The visibility evaluation method was performed for the absorbent pad size used in the evaluation: the width was 50mm, and the range to be observed at the wound site was set to 30mm wide at the center, and the evaluation was performed by dividing the opening area (visible area) by the ratio of the range to be observed at the wound site (30mm wide).

< evaluation criteria >

X: the visible area is less than 25% of the area to be observed at the wound site (30mm wide)

And (delta): the visible area is 25% or more and 27% or less with respect to the range to be observed at the wound site (30mm width)

Good: the visible area is 27% or more of the area to be observed at the wound site (30mm width)

Suitability for cutting in shedding

< evaluation step >

In addition, regarding suitability in cutting, the offset length of the dimension is measured when the workpiece is cut to a predetermined dimension.

< evaluation criteria >

X: the offset length of the pitch is 1.0mm or more,

and the offset length of the cutting size is more than or equal to 1.5mm

O: the offset length of the pitch is less than 0.5mm,

and the offset length of the cutting size is less than 1.1mm

[ Table 2]

*1: the opening pattern was set to have a width of 10mm × a height of 30mm, and the inclination angle was fixed at 40 °.

*2: the open area is the sum of the values for each absorbent pad.

*3: water absorption evaluation x: less than 0.16g/cm²O: greater than or equal to 0.16g/cm²

*4: visibility evaluation x: less than 25% of the range to be observed at the wound site

And (delta): more than or equal to 25 percent and less than 27 percent

O: greater than or equal to 27 percent

*5: suitability for cutting in opening processing

O: the offset length of the pitch is less than 0.5mm, and the offset length of the cutting size is less than 1.1mm

And (delta): the offset length of the pitch is not less than 0.5mm and less than 1.0mm, and the offset length of the cutting size is not less than 1.1mm and less than 1.5mm

X: the offset length of the pitch is 1.0mm or more, and the offset length of the cutting size is 1.5mm or more

Claims

1. A wound dressing, characterized by:

a super absorbent pad having a laminate structure comprising a polyester nonwoven fabric layer/water absorbent layer,

wherein the water absorption layer is composed of high water absorption fiber, polypropylene fiber and polyethylene adhesive,

the high water absorption pad is provided with a through opening part.

2. The wound dressing according to claim 1, wherein the water-absorbent layer is composed of, in mass ratio, super-absorbent fibers, polypropylene fibers, polyethylene binder, more than 30 mass% and less than 50 mass%, 40 mass% or more and less than 55 mass%, more than 10 mass% and less than 30 mass% (wherein the total of the super-absorbent fibers, polypropylene fibers, and polyethylene binder is 100 mass%).

3. The wound dressing of claim 1, wherein the superabsorbent absorbent pad has a weight per unit area of 200 to 400g/m²The thickness is 1.0-3.0 mm.

4. A wound dressing, especially a wound dressing with a super absorbent pad, wherein the super absorbent pad comprises a laminated structure of a non-woven fabric layer/a water absorbent layer, is characterized in that:

5. The wound dressing of claim 1 or 4,

the size of each opening in the opening part is 10-500 mm²。

6. The wound dressing of claim 1 or 4,

the opening part has a shape of triangle, quadrangle, rectangle, parallelogram, rhombus, circle, ellipse, crescent, horseshoe, ring and combination thereof.

7. The wound dressing of claim 1 or 4,

the total area of the upper surface of the super absorbent pad is set to 100%, and the total area of all the openings is set to 17% or more and 39% or less.